More Power Or My Imagination_

Maybe.

The various octane ratings have essentially the same energy per gallon. If the lower octane is causing detonation or pre ignition (death rattle) you will be losing usable power. For my car, I go for the better, or higher level of detergent, which is usually Chevron in the US. For what it's worth, octane rating is tightly regulated. Detergents are not.

Thank you Roger. Good information.